218-08-6

We disclose a new Br?nsted acid promoted quinoline synthesis, proceeding via homo-diaza-Cope rearrangement of N-aryl-N′-cyclopropyl hydrazines. Our strategy can be considered a homologation of Fischer's classical indole synthesis and delivers 6-membered N-heterocycles, including previously inaccessible pyridine derivatives. This approach can also be used as a pyridannulation methodology toward constructing polycyclic polyheteroaromatics. A computational analysis has been employed to probe plausible activation modes and to interrogate the role of the catalyst.

A versatile π-extension reaction was developed based on the three-component cross-coupling of aryl halides, 2-haloarylcarboxylic acids, and norbornadiene. The transformation is driven by the direction and subsequent decarboxylation of the carboxyl group, while norbornadiene serves as an ortho-C?H activator and ethylene synthon via a retro-Diels–Alder reaction. Comprehensive DFT calculations were performed to account for the catalytic intermediates.

This paper reports an investigation of photochemical cyclodehydrogenation for the preparation of polycyclic azaarenes. Various naphthoquinolines and naphthoisoquinolines were obtained from 2-, 3-, and 4-[2-(1- and 2-naphthyl)vinyl]pyridine. 4-[2-(3-Phenanthryl)vinyl]pyridine gave pyreno[1,10-hij]isoquinoline. An efficient preparation of (2-arylvinyl)pyridines is described. Georg Thieme Verlag Stuttgart.

The thermodynamic and kinetic parameters of the elctron transfer (ET) to benzyl phenyl sulfide in DMF have been determined by cyclic voltammetry.The heterogeneous ET has been studied at three different electrodes: Hg, Pt, and glassy carbon.The activation parameters, namely the standard rate constant and the transfer coefficient, corrected for the double-layer contribution, show no significant difference for the three materials.The rate constants for the homogeneous ET to benzyl phenyl sulfide from eight electrogenerated anion radicals have been determined and compared with the corresponding reaction free energies, according to the current theories of the ET process.The results indicate that the ET is an endergonic process driven by a fast bond breaking of the ET product.Both the homogeneous and the heterogeneous reactions are consistent with an outer-sphere adiabatic electron-exchange process, characterized by a relatively high activation free energy.To account for the latter, inner reorganization energies must be considered, together with solvent reorganization.This is an agreement with the easy breaking of the C-S bond in the primari ET product.